A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines.
The high pressure turbine drives the high pressure compressor through an outer shaft to form a high spool, and the low pressure turbine drives the low pressure compressor through an inner shaft to form a low spool. The fan section may also be driven by the low inner shaft. An interaction between shafts of the high and low spool is considered for extreme operational conditions to safeguard against possible inter-shaft contact and wear.
Accordingly, turbine engine manufacturers continue to seek further improvements to engine performance including improvements that consider potential interactions between relative rotating components during extreme operational conditions.